Bowel ischaemia-reperfusion-induced liver and lung injury: The fundamental role of eicosanoids and xanthine oxidase-generated oxygen free radicals

Objective: To assess complementary induction of remote organ injury following bowel ischaemia-reperfusion by eicosanoids and xanthine oxidase. Design: Randomized, controlled, animal study. Setting: Hospital-based animal research facility. Materials: 40 rats in 5 groups. Interventions: Sham laparotomy, laparotomy and superior mesenteric artery occlusion (ischaemia 1h) and reperfusion (3h) or laparotomy and arterial occlusion and reperfusion in rats treated with thromboxane synthase inhibitor OKY-046, leukotrienes synthase inhibitor diethylcarbamazine or xanthine oxidase inhibitor allopurinol. Main outcome measures: Bowel, liver and lung wet: dry weight ratio, tissue: circulation albumin I¹²⁵ permeability index, polymorphonuclear neutrophils tissue counts. Results: Ischaemia intestinal and lungs wet: dry ratios increased by 50% over sham or treatment groups; liver ratios were similar. Albumin indexes in ischaemia organs were 1.5-3 times more than shams and treatment values, and allopurinol normalized it best. Neutrophils counts in all ischaemia organs were double that of shams; allopurinol prevented sequestration completely, eicosanoids inhibitors did so partially. Conclusions: Xanthine oxidase initiated remote organ injury following bowel ischaemia-reperfusion. Allopurinol prevented it entirely while eicosanoids inhibitors only partially.